text: Enantiopure, planar chiral chromium arene complexes can be synthesized using several strategies. Diastereoselective complexation of a chiral, non-racemic arene to chromium is one such strategy. In the example in equation (5), enantioselective Corey-Itsuno reduction sets up a diastereoselective ligand substitution reaction. After complexation, the alcohol is reduced with triethylsilane.
  A second strategy involves enantioselective ortho-lithiation and in situ quenching with an electrophile. Isolation of the lithium arene and subsequent treatment with TMSCl led to lower enantioselectivities.
  Site-selective conjugate addition to chiral aryl hydrazone complexes can also be used for the enantioselective formation of planar chiral chromium arenes. Hydride abstraction neutralizes the addition product, and treatment with acid cleaves the hydrazone.